SIRIUS S0 power contactor, screw terminals, varistor suppression
The Siemens 3RT1024-1CP04 is a SIRIUS S0-frame power contactor for motor switching in control panels, with screw-type main circuit terminals and a built-in varistor surge suppressor. Rated motor output reaches 7.5 kW at both 500 V and 690 V, with an AC-4 switching current of 12.5 A at 400 V — this is the reversing or inching duty rating, not the continuous AC-3 figure, so it governs frequent jogging applications.
Type 1 coordination allows a 63 A gL/gG fuse. The varistor integrated across the coil suppresses voltage spikes during de-energization, reducing stress on the control circuit. Auxiliary contact ratings are specified per voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 0.3 A at 220 V — the DC switching curve drops sharply above 60 V (2 A at 60 V, 1 A at 110 V). Use these numbers for pilot duty and PLC input circuits, not the main contact ratings.
Environmental and physical fit
Dimensions are 88 mm height, 45 mm width, and 140 mm depth — the depth is the critical clearance behind the DIN rail for wiring and arc chamber ventilation. Side-by-side mounting is allowed without derating if ambient stays within limits.